I've never fished a river so cannot answer that one. As the water cools and the fish bunch up it may be a bit harder getting on 'em but once you do they'll pretty much stay in that area until something changes. The fish are following the shad in the lakes here now so finding the bait is the key. It also helps if you hear some good fishing reports in certain areas of the lake to help you pinpoint a decent place to start. I always set my lights the same...about even with the bottom of my boat (a foot under the surface). That never changes for me. As I say...it may take a few trips to get on top of some good action so dont get discouraged quickly. Stay after 'em and you'll find 'em. Then the fight begins...